12 



RANDOM NOTES ON NATURAL HISTORY. 



feet wide, and 104 feet above the adjoining 

 meadows. We cannot measure its deptii. 

 What one sees here is the mere summit of 

 a mountain larger and higher than anj- moun- 

 tain on the face of the earth. 



The ore is full of distinct crj'stals of feld- 

 spar, and is beautifullj- porphyritic, forming, 

 when polished, ver^' fine specimens. This 

 immense mass of Titanic Magnetyte looks 

 as if it had been thrust up bodily through 

 the earth's crust ; through gneiss and sie- 

 nite on the north, and granite and horn- 

 blende on the south. But, like lava, it came 

 up melted through a fissure in the earth dur- 

 iug the great disturbance millions of 3'ears 

 ago, that split open the Atlantic coast from 

 Nova Scotia to South Carolina. Oozing out 

 of the narrow crack which a man might 

 have straddled, it heaped itself up in a great 

 hill, as the greenstone hills and mountains 

 were formed, a hill immensely larger and 

 higher than it is at present. The depth of 

 the liquid source of the erupted mass is un- 

 known, but as the movement was almost 

 continental it must have been hundreds of 

 miles beneath the surface. There are vast 

 caverns, mammoth caves, in the generally 

 solid interior of the globe, in which lakes of 

 fire and seas of melted minerals surge and 

 roar unheard, except as earthquakes and 

 volcanos speak. 



The only analysis of the ore at command is 

 Dr. Jackson's, who in 1840 made a geolog- 

 ical survey of the state. Hardlj' anything 

 is of more need to-day than a new and 

 thorough geological survey to develop the 

 latent mineral resources and promote the 

 industrial prosperity of the state. Nobody 

 knows what there is an inch underground 

 anywhere. There are productive mines and 

 quarries yet to be discovered. 



Analysis: Per-oxide of iron, 27.60 ; Pro- 

 toxide do, 12.40; Silicic acid, 23.00; Ti- 

 tanic acid, 15.30; Alumina, 13.10; Mag- 

 nesia, 4.00; Manganese, 2.00; Water and 

 loss, 2.60; = 100.00. 



The feldspar in this rock is translucent, 

 and of a dark green color, looking like ser- 

 pentine. It is triclinic. With a good lens 

 the striae of every crystal are visible. The 

 crystals are rudely defined, not clearly cut. 

 All of them enclose particles of the iron 

 which disturbed the crystallization. The 

 largest seldom measure more than three- 

 eighths of an inch in length. The feldspar, 

 we believe, is a microlinic Labradorite. We 



have observed in several polished specimens, 

 bright and chatoyant reflections from within. 



The specific gravity of the mineral is 

 below that of most iron ores, being about 

 3.86. It is too poor and refractory to be 

 worked profitably. It is excessively tough, 

 and immense quantities were shipped to 

 New York some years ago for the construc- 

 tion of fortifications in the harbor. 



Its distribution locally is a matter of 

 special interest, afllbrding as it does, defi- 

 nite and decisiA'c evidence of the Glacial or 

 Drift period, and of the gigantic forces 

 employed in splitting up " the unwedgeable 

 and gnarled" ore, and transporting it in 

 lumps weighing twelve and fifteen tons so 

 many miles. 



The rock is (1) distinguished from every 

 other kind in the world by its peculiar 

 appearance, structure and composition. (2) 

 No fragments of it are scattered to the 

 north, to the east, or west of the hill ; 

 while to the south they occur profusely' of 

 ever}^ size. The stone walls of farms and 

 roads consist largely of them. The white- 

 spotted boulders are common all the way 

 to Providence, and, decreasing in size, ex- 

 tend to Bristol, Warwick Neck, and New- 

 port, even, where they are only a few 

 inches in diameter, having been freighted 

 fortj'-five miles in a direction four or five 

 degrees east of south. (3) A cubic foot of 

 the ore weighs 240 1-2 lbs. Boulders are 

 known to exist in swamps and woods to 

 the north from the Friends' College to 

 Pawtucket and beyond, weighing from two 

 and three to twelve and fifteen tons each. 



(4) Some of these masses are merelj' 

 smoothed and scratched ; others are grooved 

 and furrowed also by the ledges over which 

 they were slowl}- but irresistibly pushed and 

 pressed by an embracing superincumbent 

 mass of ice two miles in thickness. These 

 marks correspond to the diluvial scratches 

 and grooves observable wherever the rocks 

 in situ south of the hill are exposed. Noth- 

 ing, we believe, but the Glacial Theory-, can 

 account for the distribution of this dlstinct- 

 ive ore. 



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